The invention relates to circuit board assemblies which include an electrical disconnect arm for removably connecting a set of wires to a set of terminals which are disposed along one edge of an electrical circuit board.
In electrical apparatus such as solid state controllers, numerical control systems, programmable controllers, digital computers and communications equipment, the circuit components are mounted on one or more circuit boards which are closely spaced to one another within a rack or frame and are interconnected by a wire harness or "mother board". In numerical control systems and programmable controllers some of the circuit boards are also connected to input and output (I/O) devices. These I/O hardware interface circuit boards have often been mounted in an I/O rack apart from other circuit boards in the system, such as memory circuit boards and processor circuit boards, which have been mounted in a processor rack. While this is advantageous in some applications, such as one requiring location of several I/O racks in areas remote from the processor rack, in other applications it is advantageous to have a system combining the circuit boards in a single rack thereby reducing the size and amount of hardware in the system.
The connection between I/O circuit boards and external devices may involve hundreds or even thousands of wires. To disconnect these wires and to expose each I/O circuit board for inspection, repair and replacement, swinging arm connectors have been devised. These connectors are pivotably mounted for swinging motion between an operating position in which the connectors are plugged into an associated circuit board and a maintenance position in which the connectors are unplugged and swung to a position that permits removal of the circuit boards. One such connector is disclosed by William B. Springer et al in U.S. Pat. No. 3,992,654 entitled "Disconnect Arm for Electrical Equipment".